The present invention relates to recording apparatus. More particularly, it relates to a recording apparatus for light sensitive recording media which is developed by the application of heat to a photographic emulsion.
Heretofore, there have been provided recording apparatus for heat-developed light-sensitive recording media; a so called dry silver process. In such previous devices, the light sensitive medium is subjected to a light image to impart a latent image thereto. The exposed medium is then passed over a heated platen to develop the latent image. In that apparatus and process, the transfer of heat through the backing of the medium was relatively slow. The distribution of heat was difficult to control and, because there must be a significant spatial separation between the heating station and the exposure station, there was a significant wastage of recording media.
Subsequently there has been provided a recording medium of the so called dry silver type wherein there is provided an electrically conductive layer either in or on the backing. In a prior art recorder utilizing that improved recording medium, the exposed record member bearing a latent image is passed over a series of spaced rollers with the roller in contact with the conductive backing. The rollers, themselves, are of conductive material with an electrical potential alternately applied thereto. As the record member is passed over the rollers, an electrical current is passed through the conductive backing, generating sufficient heat within the backing to effect a development of the images on the film. That system, shown in U.S. Pat. No. 3,887,787, is a continuous process. As such the heating current is continuously flowing through the backing layer of the record member simultaneously with the exposure of the emulsion side of the record member to the light patterns. The coincidence of the exposure and the application of the heating current to the record member in close proximity to the exposure area tends to result in a combination of radio frequency interference from the light image source, i.e. CRT, and a high voltage from the developer near the imaging station, both tending to have deleterious effects on the record.